// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
// Distributed under the MIT License (http://opensource.org/licenses/MIT)

#pragma once

#ifndef SPDLOG_HEADER_ONLY
#include <spdlog/details/os.h>
#endif

#include <spdlog/common.h>

#include <algorithm>
#include <array>
#include <chrono>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <string>
#include <sys/stat.h>
#include <sys/types.h>
#include <thread>

#ifdef _WIN32
#include <spdlog/details/windows_include.h>
#include <fileapi.h>  // for FlushFileBuffers
#include <io.h>       // for _get_osfhandle, _isatty, _fileno
#include <process.h>  // for _get_pid

#ifdef __MINGW32__
#include <share.h>
#endif

#if defined(SPDLOG_WCHAR_TO_UTF8_SUPPORT) || defined(SPDLOG_WCHAR_FILENAMES)
#include <cassert>
#include <limits>
#endif

#include <direct.h>  // for _mkdir/_wmkdir

#else  // unix

#include <fcntl.h>
#include <unistd.h>

#ifdef __linux__
#include <sys/syscall.h>  //Use gettid() syscall under linux to get thread id

#elif defined(_AIX)
#include <pthread.h>  // for pthread_getthrds_np

#elif defined(__DragonFly__) || defined(__FreeBSD__)
#include <pthread_np.h>  // for pthread_getthreadid_np

#elif defined(__NetBSD__)
#include <lwp.h>  // for _lwp_self

#elif defined(__sun)
#include <thread.h>  // for thr_self
#endif

#endif  // unix

#if defined __APPLE__
#include <AvailabilityMacros.h>
#endif

#ifndef __has_feature       // Clang - feature checking macros.
#define __has_feature(x) 0  // Compatibility with non-clang compilers.
#endif

namespace spdlog {
namespace details {
    namespace os {

        SPDLOG_INLINE spdlog::log_clock::time_point now() SPDLOG_NOEXCEPT
        {
#if defined __linux__ && defined SPDLOG_CLOCK_COARSE
            timespec ts;
            ::clock_gettime(CLOCK_REALTIME_COARSE, &ts);
            return std::chrono::time_point<log_clock, typename log_clock::duration>(
                std::chrono::duration_cast<typename log_clock::duration>(std::chrono::seconds(ts.tv_sec) + std::chrono::nanoseconds(ts.tv_nsec)));

#else
            return log_clock::now();
#endif
        }
        SPDLOG_INLINE std::tm localtime(const std::time_t& time_tt) SPDLOG_NOEXCEPT
        {
#ifdef _WIN32
            std::tm tm;
            ::localtime_s(&tm, &time_tt);
#else
            std::tm tm;
            ::localtime_r(&time_tt, &tm);
#endif
            return tm;
        }

        SPDLOG_INLINE std::tm localtime() SPDLOG_NOEXCEPT
        {
            std::time_t now_t = ::time(nullptr);
            return localtime(now_t);
        }

        SPDLOG_INLINE std::tm gmtime(const std::time_t& time_tt) SPDLOG_NOEXCEPT
        {
#ifdef _WIN32
            std::tm tm;
            ::gmtime_s(&tm, &time_tt);
#else
            std::tm tm;
            ::gmtime_r(&time_tt, &tm);
#endif
            return tm;
        }

        SPDLOG_INLINE std::tm gmtime() SPDLOG_NOEXCEPT
        {
            std::time_t now_t = ::time(nullptr);
            return gmtime(now_t);
        }

        // fopen_s on non windows for writing
        SPDLOG_INLINE bool fopen_s(FILE** fp, const filename_t& filename, const filename_t& mode)
        {
#ifdef _WIN32
#ifdef SPDLOG_WCHAR_FILENAMES
            *fp = ::_wfsopen((filename.c_str()), mode.c_str(), _SH_DENYNO);
#else
            *fp = ::_fsopen((filename.c_str()), mode.c_str(), _SH_DENYNO);
#endif
#if defined(SPDLOG_PREVENT_CHILD_FD)
            if (*fp != nullptr)
            {
                auto file_handle = reinterpret_cast<HANDLE>(_get_osfhandle(::_fileno(*fp)));
                if (!::SetHandleInformation(file_handle, HANDLE_FLAG_INHERIT, 0))
                {
                    ::fclose(*fp);
                    *fp = nullptr;
                }
            }
#endif
#else  // unix
#if defined(SPDLOG_PREVENT_CHILD_FD)
            const int mode_flag = mode == SPDLOG_FILENAME_T("ab") ? O_APPEND : O_TRUNC;
            const int fd = ::open((filename.c_str()), O_CREAT | O_WRONLY | O_CLOEXEC | mode_flag, mode_t(0644));
            if (fd == -1)
            {
                return true;
            }
            *fp = ::fdopen(fd, mode.c_str());
            if (*fp == nullptr)
            {
                ::close(fd);
            }
#else
            *fp = ::fopen((filename.c_str()), mode.c_str());
#endif
#endif

            return *fp == nullptr;
        }

        SPDLOG_INLINE int remove(const filename_t& filename) SPDLOG_NOEXCEPT
        {
#if defined(_WIN32) && defined(SPDLOG_WCHAR_FILENAMES)
            return ::_wremove(filename.c_str());
#else
            return std::remove(filename.c_str());
#endif
        }

        SPDLOG_INLINE int remove_if_exists(const filename_t& filename) SPDLOG_NOEXCEPT { return path_exists(filename) ? remove(filename) : 0; }

        SPDLOG_INLINE int rename(const filename_t& filename1, const filename_t& filename2) SPDLOG_NOEXCEPT
        {
#if defined(_WIN32) && defined(SPDLOG_WCHAR_FILENAMES)
            return ::_wrename(filename1.c_str(), filename2.c_str());
#else
            return std::rename(filename1.c_str(), filename2.c_str());
#endif
        }

        // Return true if path exists (file or directory)
        SPDLOG_INLINE bool path_exists(const filename_t& filename) SPDLOG_NOEXCEPT
        {
#ifdef _WIN32
#ifdef SPDLOG_WCHAR_FILENAMES
            auto attribs = ::GetFileAttributesW(filename.c_str());
#else
            auto attribs = ::GetFileAttributesA(filename.c_str());
#endif
            return attribs != INVALID_FILE_ATTRIBUTES;
#else  // common linux/unix all have the stat system call
            struct stat buffer;
            return (::stat(filename.c_str(), &buffer) == 0);
#endif
        }

#ifdef _MSC_VER
// avoid warning about unreachable statement at the end of filesize()
#pragma warning(push)
#pragma warning(disable : 4702)
#endif

        // Return file size according to open FILE* object
        SPDLOG_INLINE size_t filesize(FILE* f)
        {
            if (f == nullptr)
            {
                throw_spdlog_ex("Failed getting file size. fd is null");
            }
#if defined(_WIN32) && !defined(__CYGWIN__)
            int fd = ::_fileno(f);
#if defined(_WIN64)  // 64 bits
            __int64 ret = ::_filelengthi64(fd);
            if (ret >= 0)
            {
                return static_cast<size_t>(ret);
            }

#else  // windows 32 bits
            long ret = ::_filelength(fd);
            if (ret >= 0)
            {
                return static_cast<size_t>(ret);
            }
#endif

#else  // unix
// OpenBSD and AIX doesn't compile with :: before the fileno(..)
#if defined(__OpenBSD__) || defined(_AIX)
            int fd = fileno(f);
#else
            int fd = ::fileno(f);
#endif
// 64 bits(but not in osx, linux/musl or cygwin, where fstat64 is deprecated)
#if ((defined(__linux__) && defined(__GLIBC__)) || defined(__sun) || defined(_AIX)) && (defined(__LP64__) || defined(_LP64))
            struct stat64 st;
            if (::fstat64(fd, &st) == 0)
            {
                return static_cast<size_t>(st.st_size);
            }
#else  // other unix or linux 32 bits or cygwin
            struct stat st;
            if (::fstat(fd, &st) == 0)
            {
                return static_cast<size_t>(st.st_size);
            }
#endif
#endif
            throw_spdlog_ex("Failed getting file size from fd", errno);
            return 0;  // will not be reached.
        }

#ifdef _MSC_VER
#pragma warning(pop)
#endif

        // Return utc offset in minutes or throw spdlog_ex on failure
        SPDLOG_INLINE int utc_minutes_offset(const std::tm& tm)
        {
#ifdef _WIN32
#if _WIN32_WINNT < _WIN32_WINNT_WS08
            TIME_ZONE_INFORMATION tzinfo;
            auto rv = ::GetTimeZoneInformation(&tzinfo);
#else
            DYNAMIC_TIME_ZONE_INFORMATION tzinfo;
            auto rv = ::GetDynamicTimeZoneInformation(&tzinfo);
#endif
            if (rv == TIME_ZONE_ID_INVALID)
                throw_spdlog_ex("Failed getting timezone info. ", errno);

            int offset = -tzinfo.Bias;
            if (tm.tm_isdst)
            {
                offset -= tzinfo.DaylightBias;
            }
            else
            {
                offset -= tzinfo.StandardBias;
            }
            return offset;
#else

#if defined(sun) || defined(__sun) || defined(_AIX) || (defined(__NEWLIB__) && !defined(__TM_GMTOFF)) || (!defined(_BSD_SOURCE) && !defined(_GNU_SOURCE))
            // 'tm_gmtoff' field is BSD extension and it's missing on SunOS/Solaris
            struct helper
            {
                static long int calculate_gmt_offset(const std::tm& localtm = details::os::localtime(), const std::tm& gmtm = details::os::gmtime())
                {
                    int local_year = localtm.tm_year + (1900 - 1);
                    int gmt_year = gmtm.tm_year + (1900 - 1);

                    long int days = (
                        // difference in day of year
                        localtm.tm_yday -
                        gmtm.tm_yday

                        // + intervening leap days
                        + ((local_year >> 2) - (gmt_year >> 2)) - (local_year / 100 - gmt_year / 100) +
                        ((local_year / 100 >> 2) - (gmt_year / 100 >> 2))

                        // + difference in years * 365 */
                        + static_cast<long int>(local_year - gmt_year) * 365);

                    long int hours = (24 * days) + (localtm.tm_hour - gmtm.tm_hour);
                    long int mins = (60 * hours) + (localtm.tm_min - gmtm.tm_min);
                    long int secs = (60 * mins) + (localtm.tm_sec - gmtm.tm_sec);

                    return secs;
                }
            };

            auto offset_seconds = helper::calculate_gmt_offset(tm);
#else
            auto offset_seconds = tm.tm_gmtoff;
#endif

            return static_cast<int>(offset_seconds / 60);
#endif
        }

        // Return current thread id as size_t
        // It exists because the std::this_thread::get_id() is much slower(especially
        // under VS 2013)
        SPDLOG_INLINE size_t _thread_id() SPDLOG_NOEXCEPT
        {
#ifdef _WIN32
            return static_cast<size_t>(::GetCurrentThreadId());
#elif defined(__linux__)
#if defined(__ANDROID__) && defined(__ANDROID_API__) && (__ANDROID_API__ < 21)
#define SYS_gettid __NR_gettid
#endif
            return static_cast<size_t>(::syscall(SYS_gettid));
#elif defined(_AIX)
            struct __pthrdsinfo buf;
            int reg_size = 0;
            pthread_t pt = pthread_self();
            int retval = pthread_getthrds_np(&pt, PTHRDSINFO_QUERY_TID, &buf, sizeof(buf), NULL, &reg_size);
            int tid = (!retval) ? buf.__pi_tid : 0;
            return static_cast<size_t>(tid);
#elif defined(__DragonFly__) || defined(__FreeBSD__)
            return static_cast<size_t>(::pthread_getthreadid_np());
#elif defined(__NetBSD__)
            return static_cast<size_t>(::_lwp_self());
#elif defined(__OpenBSD__)
            return static_cast<size_t>(::getthrid());
#elif defined(__sun)
            return static_cast<size_t>(::thr_self());
#elif __APPLE__
            uint64_t tid;
// There is no pthread_threadid_np prior to Mac OS X 10.6, and it is not supported on any PPC,
// including 10.6.8 Rosetta. __POWERPC__ is Apple-specific define encompassing ppc and ppc64.
#ifdef MAC_OS_X_VERSION_MAX_ALLOWED
            {
#if (MAC_OS_X_VERSION_MAX_ALLOWED < 1060) || defined(__POWERPC__)
                tid = pthread_mach_thread_np(pthread_self());
#elif MAC_OS_X_VERSION_MIN_REQUIRED < 1060
                if (&pthread_threadid_np)
                {
                    pthread_threadid_np(nullptr, &tid);
                }
                else
                {
                    tid = pthread_mach_thread_np(pthread_self());
                }
#else
                pthread_threadid_np(nullptr, &tid);
#endif
            }
#else
            pthread_threadid_np(nullptr, &tid);
#endif
            return static_cast<size_t>(tid);
#else  // Default to standard C++11 (other Unix)
            return static_cast<size_t>(std::hash<std::thread::id>()(std::this_thread::get_id()));
#endif
        }

        // Return current thread id as size_t (from thread local storage)
        SPDLOG_INLINE size_t thread_id() SPDLOG_NOEXCEPT
        {
#if defined(SPDLOG_NO_TLS)
            return _thread_id();
#else  // cache thread id in tls
            static thread_local const size_t tid = _thread_id();
            return tid;
#endif
        }

        // This is avoid msvc issue in sleep_for that happens if the clock changes.
        // See https://github.com/gabime/spdlog/issues/609
        SPDLOG_INLINE void sleep_for_millis(unsigned int milliseconds) SPDLOG_NOEXCEPT
        {
#if defined(_WIN32)
            ::Sleep(milliseconds);
#else
            std::this_thread::sleep_for(std::chrono::milliseconds(milliseconds));
#endif
        }

// wchar support for windows file names (SPDLOG_WCHAR_FILENAMES must be defined)
#if defined(_WIN32) && defined(SPDLOG_WCHAR_FILENAMES)
        SPDLOG_INLINE std::string filename_to_str(const filename_t& filename)
        {
            memory_buf_t buf;
            wstr_to_utf8buf(filename, buf);
            return SPDLOG_BUF_TO_STRING(buf);
        }
#else
        SPDLOG_INLINE std::string filename_to_str(const filename_t& filename) { return filename; }
#endif

        SPDLOG_INLINE int pid() SPDLOG_NOEXCEPT
        {
#ifdef _WIN32
            return conditional_static_cast<int>(::GetCurrentProcessId());
#else
            return conditional_static_cast<int>(::getpid());
#endif
        }

        // Determine if the terminal supports colors
        // Based on: https://github.com/agauniyal/rang/
        SPDLOG_INLINE bool is_color_terminal() SPDLOG_NOEXCEPT
        {
#ifdef _WIN32
            return true;
#else

            static const bool result = []() {
                const char* env_colorterm_p = std::getenv("COLORTERM");
                if (env_colorterm_p != nullptr)
                {
                    return true;
                }

                static constexpr std::array<const char*, 16> terms = {{"ansi",
                                                                       "color",
                                                                       "console",
                                                                       "cygwin",
                                                                       "gnome",
                                                                       "konsole",
                                                                       "kterm",
                                                                       "linux",
                                                                       "msys",
                                                                       "putty",
                                                                       "rxvt",
                                                                       "screen",
                                                                       "vt100",
                                                                       "xterm",
                                                                       "alacritty",
                                                                       "vt102"}};

                const char* env_term_p = std::getenv("TERM");
                if (env_term_p == nullptr)
                {
                    return false;
                }

                return std::any_of(terms.begin(), terms.end(), [&](const char* term) { return std::strstr(env_term_p, term) != nullptr; });
            }();

            return result;
#endif
        }

        // Determine if the terminal attached
        // Source: https://github.com/agauniyal/rang/
        SPDLOG_INLINE bool in_terminal(FILE* file) SPDLOG_NOEXCEPT
        {
#ifdef _WIN32
            return ::_isatty(_fileno(file)) != 0;
#else
            return ::isatty(fileno(file)) != 0;
#endif
        }

#if (defined(SPDLOG_WCHAR_TO_UTF8_SUPPORT) || defined(SPDLOG_WCHAR_FILENAMES)) && defined(_WIN32)
        SPDLOG_INLINE void wstr_to_utf8buf(wstring_view_t wstr, memory_buf_t& target)
        {
            if (wstr.size() > static_cast<size_t>((std::numeric_limits<int>::max)()) / 2 - 1)
            {
                throw_spdlog_ex("UTF-16 string is too big to be converted to UTF-8");
            }

            int wstr_size = static_cast<int>(wstr.size());
            if (wstr_size == 0)
            {
                target.resize(0);
                return;
            }

            int result_size = static_cast<int>(target.capacity());
            if ((wstr_size + 1) * 2 > result_size)
            {
                result_size = ::WideCharToMultiByte(CP_UTF8, 0, wstr.data(), wstr_size, NULL, 0, NULL, NULL);
            }

            if (result_size > 0)
            {
                target.resize(result_size);
                result_size = ::WideCharToMultiByte(CP_UTF8, 0, wstr.data(), wstr_size, target.data(), result_size, NULL, NULL);

                if (result_size > 0)
                {
                    target.resize(result_size);
                    return;
                }
            }

            throw_spdlog_ex(fmt_lib::format("WideCharToMultiByte failed. Last error: {}", ::GetLastError()));
        }

        SPDLOG_INLINE void utf8_to_wstrbuf(string_view_t str, wmemory_buf_t& target)
        {
            if (str.size() > static_cast<size_t>((std::numeric_limits<int>::max)()) - 1)
            {
                throw_spdlog_ex("UTF-8 string is too big to be converted to UTF-16");
            }

            int str_size = static_cast<int>(str.size());
            if (str_size == 0)
            {
                target.resize(0);
                return;
            }

            // find the size to allocate for the result buffer
            int result_size = ::MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, str.data(), str_size, NULL, 0);

            if (result_size > 0)
            {
                target.resize(result_size);
                result_size = ::MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, str.data(), str_size, target.data(), result_size);
                if (result_size > 0)
                {
                    assert(result_size == target.size());
                    return;
                }
            }

            throw_spdlog_ex(fmt_lib::format("MultiByteToWideChar failed. Last error: {}", ::GetLastError()));
        }
#endif  // (defined(SPDLOG_WCHAR_TO_UTF8_SUPPORT) || defined(SPDLOG_WCHAR_FILENAMES)) && \
        // defined(_WIN32)

        // return true on success
        static SPDLOG_INLINE bool mkdir_(const filename_t& path)
        {
#ifdef _WIN32
#ifdef SPDLOG_WCHAR_FILENAMES
            return ::_wmkdir(path.c_str()) == 0;
#else
            return ::_mkdir(path.c_str()) == 0;
#endif
#else
            return ::mkdir(path.c_str(), mode_t(0755)) == 0;
#endif
        }

        // create the given directory - and all directories leading to it
        // return true on success or if the directory already exists
        SPDLOG_INLINE bool create_dir(const filename_t& path)
        {
            if (path_exists(path))
            {
                return true;
            }

            if (path.empty())
            {
                return false;
            }

            size_t search_offset = 0;
            do
            {
                auto token_pos = path.find_first_of(folder_seps_filename, search_offset);
                // treat the entire path as a folder if no folder separator not found
                if (token_pos == filename_t::npos)
                {
                    token_pos = path.size();
                }

                auto subdir = path.substr(0, token_pos);

                if (!subdir.empty() && !path_exists(subdir) && !mkdir_(subdir))
                {
                    return false;  // return error if failed creating dir
                }
                search_offset = token_pos + 1;
            } while (search_offset < path.size());

            return true;
        }

        // Return directory name from given path or empty string
        // "abc/file" => "abc"
        // "abc/" => "abc"
        // "abc" => ""
        // "abc///" => "abc//"
        SPDLOG_INLINE filename_t dir_name(const filename_t& path)
        {
            auto pos = path.find_last_of(folder_seps_filename);
            return pos != filename_t::npos ? path.substr(0, pos) : filename_t{};
        }

        std::string SPDLOG_INLINE getenv(const char* field)
        {
#if defined(_MSC_VER)
#if defined(__cplusplus_winrt)
            return std::string{};  // not supported under uwp
#else
            size_t len = 0;
            char buf[128];
            bool ok = ::getenv_s(&len, buf, sizeof(buf), field) == 0;
            return ok ? buf : std::string{};
#endif
#else  // revert to getenv
            char* buf = ::getenv(field);
            return buf ? buf : std::string{};
#endif
        }

        // Do fsync by FILE handlerpointer
        // Return true on success
        SPDLOG_INLINE bool fsync(FILE* fp)
        {
#ifdef _WIN32
            return FlushFileBuffers(reinterpret_cast<HANDLE>(_get_osfhandle(_fileno(fp)))) != 0;
#else
            return ::fsync(fileno(fp)) == 0;
#endif
        }

    }  // namespace os
}  // namespace details
}  // namespace spdlog
